1. Field of the Invention
The invention relates to a method for a rapid test of the quality of grains, crushed grains, and flours, by means of measuring the gluten aggregation.
2. Description of the Related Art
In their article “Qualitätsbeschreibung von Mehlen für nicht hefegelockerte feine Backwaren” [“Quality description of flours for fine baked goods not loosened with yeast”], in: Getreide, Mehl und Brot [Grain, Flour, and Bread] 52 (1998), 2, the authors Botterbrodt, Hanneforth, Lewandrowski, and Brümmer explain that in the description of flour quality, the questions as to what characteristic data characterize the quality, and what characteristic data possess informational value for the range of use stand in the foreground. The characteristic values of flour quality, e.g. the protein content, the wet gluten content, but also those obtained from baking experiments, such as the rapid mix test (RMT), are variables known for this purpose.
In the article, in connection with rapid testing of flours, the so-called knock-out test is mentioned, which was already described for the first time in 1997, in the journal “Getreide, Mehl und Brot,” Issue 51, by the authors Hanneforth, Zwingelberg, and Gebhard. In this test, also known as the gluten aggregation test, the aggregation behavior of a flour/water suspension in a ratio of 1:1.2 to 1:1.5 is observed, using distilled water. The grain to be studied is brought to a certain temperature and weighed into the mixer top in a commercially available mixer (110 g, for example). The water is tempered to 23° C., for example, and also weighed into the mixer (132 g, for example).
The mixer is turned on and allowed to run at a medium level (at approximately 4500 rpm) for about 20 seconds. Then, the mixer top is scratched slightly, and subsequently the mixer is operated for another 20 seconds at the previous level. Then the mixer is stopped for a short time, and the actual measurement begins, whereby the mixer runs at a higher level (6250 rpm, for example). The measurement is recorded and the time period between start of measurement and end of measurement is determined. The end of the measurement is reached when the power consumption of 2 amperes is reached after the maximum. The goal and purpose of this test is to confirm wheat lots (e.g. of the E and A wheat groups) that have been delivered and marked accordingly, by means of a corresponding aggregation behavior.
For a determination of the time point of maximal gluten cross-linking, an ampere meter is connected with the mixer. As a result of the formation of the gluten lattice in the mass, the mixer experiences increasing resistance, which leads to increased power consumption and thus to an increase in the ampere number displayed.
However, a disadvantage in this method is the fact that identical electric motors can never be present in different devices, so that each device records different power consumption values, since different windings also bring different thermal general conditions with them.
Furthermore, the use of distilled water is not suitable for every sample, since it has been found that in the case of many samples, in the case of so-called weak flours, no aggregation takes place. A further disadvantage is the relatively large sample amount that is needed. Another decisive disadvantage, however, is the long testing time, whereby the preparatory method steps up to the start of the actual measurement are complicated and time-intensive.